#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
fun(char a[])
{
	int i, n = -1, j;
	for(i=0;a[i]!='\0';i++)
	{
		n = i;
		for (j = strlen(a); j >= n; j--)
			a[j + 1] = a[j];
		a[n] = '$';
		i++;
	}
	if (n == -1)
	{
		printf("\ncan not put'$'into the characters:");
		exit(1);
	}
}
main()
{
	char s[80];
	printf("\ninput the characters");
	gets(s);
	fun(s);
	printf("c:%s", s);
}